Head space adjusting and locking means for removable firearm barrels



July 15, 1947. c. E. SIMPSON 2,423,854

HEAD SPACE ADJUSTING AND LOCKING MEANS FOR REMOVABLE FIREARM BARRELSFiled Dec. 17, 1945 2 SheetsSheet l W m Md m a F \i, E 7 E m V M A? g4?N, iifiN i N Q R wa a m y 9w H Q W 0 KW 1 N w camwamw- I Suez/"M44 July15, 1&47. c. E. SIMPSON 2 5 HEAD SPACE ADJUSTING AND LOCKING MEANS FORREMOVABLE FIREARM BARRELS Filed Dec. 17, 1943 2 Sheets-Sheet 2'CLARENCEEEHMPEUN,

Patented July 15, 1947 HEAD SPACE ADJUSTING AND LOCKING MEANS FORREMOVABLE FIREARM BARRELS Clarence E. Simpson, Springfield, Mass.,assignor to the Government of the United States of America, asrepresented by the Secretary of War Application December 17, 1943,Serial No. 514,612

(Granted under the act of March- 3, 1883, as amended April 30, 1928; 3700. 757) 9 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment to me ofany royalty thereon.

This invention relates to an improvement in firearms, more particularlyto head space adjusting means and to means for enabling a quick changeof barrels.

A very serious limitation in firearms of theautomatic type, particularlyaircooled automatic firearms, is the overheating of the barrel fromfiring long continuous bursts of cartridges. Various means have beenprovided to overcome such overheating but such means have been onlypartially successful. The most satisfactory practice has been to changethe overheated barrel for another cold, unused barrel.

In the heat of battle it is essential that a firearm be kept inoperation until the crisis has passed. To do so, therefore, means thatthe hot barrel in an aircooled Weapon must be quickly detachable so thatanother barrel may be immediately replaced with a minimum loss of timein effecting such change. In providing such a quick change barrel thereare numerous inherent difiiculties to be overcome in any firearm.Foremost among such difficulties is the accumulation of manufacturingtolerances in the various related components affecting headspace of thefirearm. In fact, the manufacturing tolerance accumulations Oncomponents other than the barrels will be such that the distance fromthe head of a cartridge seated in the chamber of the barrel to the faceof the bolt will var to such a degree that in some instances the boltcannot be closed on a cartridge and hence the gun cannot be fired, whilethe other extreme is such that the face of the bolt 'does not supportthe head of the cartridge and therefore permits the case to be rupturedwhen fired.

In the past most quick change barrels for aircooled firearms utilized aninterrupted thread on the breech end of the barrel to permit rapidchanging of such barrels. With such a securing means the barrelfrequently is insecurely held because of the non-rigid support affordedby an interrupted thread. Further, an interrupted thread system forfastening the'barrel precludes all possibility of incorporation thereinof satisfactory adjustable headspace means.

Accordingly, it is an object of this inven'tion to provide a quickchange barrel attachment for a firearm incorporating an adjustableheadspacing feature to compensate for manufacturing tolerances ofcomponents afiecting headspace.

Anotherpbj'ect of this invention is to provide an improved combinationbarrel support and gas cylinder for a firearm.

Still another object of this invention is to provide a quick changebarrel attachment for a firearm having a safety feature to preventfiring of a cartridge in the barrel when the barrel is not in the lockedposition. i

The specific nature "of the invention as well as other objects andadvantages thereof will clearly a pear from a description of a preferredembodiment as shown in the accompanying drawings in which:

Fig. 1 is a partial longitudinal sectional view of a firearm showing thequick change barrel and headsp ace adjusting means.

Fig. 2 is a right end elevational view of Fi 1.

Fi 3 is a detail view partly in longitudinalsection showing the barrelin the locked position.

Fig. 4 is across sectional view taken along the plane 4# of Fig. 1.

Fig. 5 is across sectional view taken along the plane 5--5 of Fig. 1.

Fig. 6 is a cross sectional view taken along the plane 6-6 of Fig. 1.

Fig. 7 is a fragmentary detail right side view of the firearm showingthe slide blocking plunger and plunger spring.

This in vention essentially comprises a barrel, a barrel locking sleeveand a barrel locking handle. The barrel locking sleeve is threaded andis screwed into the receiver of a firearm and becomes a permanent partof the receiver. Two locking lugs are provided on the interior of thesleeve which engage corresponding locking lugs provided on the barrelwhen the barrel is inserted thr'u thesleeve and such sleeve is rotatedapproximately a quarter turn. This brings the locking lugs in the sleeveinto contact with the locking lugs on the barrel. Headspace adjustmentis readily accomplished by slightly rotating the sleeve within thereceiver in a clockwise or counterclockwise direction as necessary bymeans of thebarrel locking handle.

In Fig. 1 there isishown in asse'mbledrelation a firearm embodying thisinvention. 'A'b'arrel I is mounted in a sleeve til which is in turnmounted in a receiver 15. The sleeve I0 is a short tubular memberprovided with a left hand threaded .portion 2 on its outer periphery. Acollar 3 is provided integral with and adjacent the threaded portion 2.On the collar 3 2. lug 4 (Figs. 2 and 4) is provided to serve as a stop'for a purpose to be described. An annular groove 5 is also providedabout the periphery of sleeve llwhich is engaged by a barrel lockinghandle screw 6 in a manner to be described. On the interior surface ofbarrel sleeve I two oppositely disposed locking lugs 1 (Fig. 6) areprovided. Barrel sleeve I0 is screwed into a suitably left hand threadedhole in receiver The barrel I is provided at the breech end with twooppositely disposed locking lugs 8 (Figs. 3 and 6). A short distance tothe right of locking lugs 8 as viewed in Fig. 1 there is provided anenlarged diameter portion 9 on barrel I which forms a shoulder I I.Approximately in the center of the enlarged diameter 9 of barrel I ashallow annular groove I2 is provided which is engaged by a spring.biased plunger I3 of a barrel carrying handle IE to be described.

An operating member comprising a barrel locking handle I! (Figs. 2, 4and 5) is placed over the end of barrel sleeve I0 provided with theannular groove 5 and abuts collar 3 on barrel sleeve Ill. The barrellocking handle I'I comprises a ring or sleeve portion I8 which surroundsbarrel sleeve I0 and has an integral arm I9. Where arm I9 joins the ringportion I8 a small rectangular enlarged portion 2I is provided. In thehub 2I a threaded hole 22 is provided to receive the barrel lockinghandle screw 6. The screw 5 engages in the annular groove 5 on sleeveIIJ functioning as a removable key to retain the barrel locking handle Hin a fixed axial position on the barrel sleeve I6. A sector of the outerperiphery of the barrel sleeve I0, adjacent each side of the roove 5, isprovided with a plurality of teeth or serrations 26. The ring or sleeveI8 has an internal portion thereof, directl underneath the arm I9 of thehandle I! (Figs. 4 and 5), provided with a dovetail slot 23 in which isinserted a key 24 having axially spaced groups of teeth or serrations 25matching those on the outer periphery of the barrel sleeve I0 andadapted to engage the same to lock the handle I! in difi'erent selectedpositions of adjustment on the barrel sleeve I0 for the purpose ofadjusting the headspace of the firearm in a manner to be described.

Approximately opposite hub 2| on the outer periphery of ring portion I8there are provided serrations 21 for engagement by a spring biasedwedge-shaped tooth 28" forming part of a resilient member 28 mounted ina transverse slot 28' in receiver I5 directly underneath barrel I (Figs.1, 3, 4 and 5). The serrations 21 are provided to hold barrel lockinghandle I I in an upraised position, as shown in Fig. 5, to unlock thebarrel I to permit the same to be readily withdrawn from receiver I5 ina manner to be explained. To hold the barrel locking handle I! in thelocked or downward position, additional serrations 29 are provided onthe outer periphery of ring I8, spaced approximately 90 from serrations21, so as to engage wedge-shaped tooth 28" of the member 28 when handleI! is rotated approximately 90, as shown in Fig. 4. The integral lug 4on the collar 3 strikes a stop 40 (Figs. 2, 4 and 5) on the receiver I5,when handle I1 is raised to the unlocked position of Fig. 5. Lug 4 is sopositioned that the wedge-shaped tooth 28 on the member 28 will alwaysengage one of the serrations 21 of handle Il when handle I! is raised tothe unlocked position. The stop 40 comprises a pin forcibly driven intoa suitable hole in receiver I5 susbtantially underneath ring I8 ofhandle I! as shown in Figs. 4 and 5.

The barrel carrying handle I6 (Fig. 1) comprises a bracket I4 and a grip30. The bracket I4 is mounted on the enlarged diameter portion 9 ofbarrel I and is free to rotate thereon. The bracket I4 is retained onbarrel I by the spring biased plunger I3 which engages the annulargroove I2 on the enlarged diameter portion 9 of barrel I. A suitablenotch 4I is provided in the groove I2 so that the handle I6 may besecured in an upright position to facilitate insertion of the barrelinto barrel sleeve ID. A smart blow on the side of grip 30 will readilydisengage plunger I3 from the notch however permitting the handle It tobe rotated out of the line of sight of the firearm to a lowered positionwhereupon the plunger I3 will then engage another notch (not shown)thereby retaining the handle I6 at such a lowered position untilforcibly re moved therefrom.

Barrel I is further supported by a barrel support bracket 3I (Fig. 1)which surrounds barrel I at a distance approximately one-third thelength of the barrel from the breech end of the barrel. The bracket 3|is secured to barrel I as by a pin 32 and surrounds a gas port 33 inbarrel I. The bracket 3| projects downwardly and is provided with atransverse hole 34 to receive the end of a gas cylinder tube plug 35.The gas cylinder tube plug 35 is secured to the end of a gas cylindertube 39 as by threads 35a. The gas cylinder tube 36 is in turn rigidlysecured in a suitable manner to the end of receiver I5. Thus the gascylinder tube 36 thru the bracket 3| provides additional support tobarrel I. A hole 31 provided in the bracket 3I communicates with gasport 33 in barrel I and with an axial hole 38 in gas cylinder tube plug35 to admit a portion of the gases of combustion to the face of anoperating piston 39 within gas cylinder tube 36, Piston 39 is suitablyconnected to an operating slide 43.

A plunger 42 (Figs. 4 and 7) in receiver I5 is provided to blockoperating slide 43 to prevent accidental discharge of the weapon whenbarrel locking handle I! is in the raised or unlocked position. One endof the plunger 42 is provided with a substantially oval-shaped head 44slidably mounted in a similarly shaped transverse recess 45 in receiverI5, and the opposite end of the plunger 42 is slidably carried in anopening 42, also in the receiver I5 but positioned directly opposite tothe recess 45, as shown in Fig. 4. Recess 45 communicates with thehollow interior of receiver I5. The plunger 42 is biased by a fiatspring 46 transversely of the receiver I5 to engage the handle I! whensuch handle is in the locked position as shown in Figs. 2 and 4. Spring46 is horizontally mounted on the right side of receiver I5 as shown inFig. '7 by a screw 41 which passes thru a slot 48 in one end of spring46 and into a threaded hole in receiver I5. The other end of spring 46bears against head 44 of plunger 42. Hence when handle I1 is notproperly abutting the receiver I5. as in Fig. 4, the spring 46 biasesthe plunger 42 to the left, as viewed in Fig. 4, causing the head 44 toenter the hollow interior of receiver I5. The slide 43 is provided witha notch 43 and when in battery position this notch registers with thehead 44. Thus, when the handle I7 is not in its final position, as shownin Fig. 4, the head of the biased plunger 42 enters the notch 43,thereby blocking slide 43 against longitudinal movement.

The firearm shown in Fig, 1 embodying the headspace adjusting featureand barrel previously described is readily adjusted for headspace in thefollowing manner:

As shown in Fig. 1, the barrel lugs 8 fully engage lugs I of barrelsleeve I0. As the sleeve I0 abuts barrel shoulder II, any rotationalmovement of sleeve I would produce a longitudinal movement of barrel Iproportional to the lead of the thread of sleeve I0 either to the rightor left as viewed in Fig. 1 depending upon the direction of rotation ofsleeve I0. As such longitudinal movement of barrel I can be obtained brotating sleeve II] the headspace of the firearm can thereby be readilyadjusted.

To adjust the headspace of the firearm, the barrel locking handle I! israised as shown in Fig. 5. A conventional headspace gage (not shown) .ora cartridge 60 of known dimensions is inserted in the chamber. Thebarrel locking handle I! is then rotated downwardly until arm I9 strikesthe corner of receiver I5, as in Fig. 4. If handle .I"i cannot belowered to this position the headspace is, therefore, too tight andbarrel I cannot be locked into receiver I5. Handle I? is then raised,barrel I is moved slightly forward, screw 6 is unfastened, and handle I?is moved axially to the right as viewed in Fig. 1, until serrations '25on the key 24 no longer engage the serrations 26 on the sleeve Iii.Handle IT, and hence the ring or sleeve I8, is rotated slightly in aclockwise direction, as viewed in Figs. 2, 4, and 5, relative to thebarrel sleeve Iii until the serrated portion 25 is advanced one or moreserrations relative to the serrated sector 26. Thereupon, handle I 'Iand sleeve II] are again axially moved 'to the left, as viewed in Figs.1 and 3; whereupon the barrel I can be moved back to its originalposition. If handle IT can be lowered to the closed position so that armis strikes the corner .of the receiver It the firearm will be correctlyheadspaced. If not, the procedure of moving the serrations 25 of the key2d relative to the serrated sectors 26 is repeated until handle I! canbe rotated to its proper locking position shown in Fig. 4. It will'beappreciated that this indication of proper headspace adjustment isdependent upon the face of the bolt, when in full battery position,engaging the end of the headspace gage or cartridge in the chamber ofthe barrel. Conversely if handle I'I closes too easily when headspaceadjustment is first made the headspace is too great and a similarprocedure must be repeated until barrel locking handle II will justclose. In this case however sleeve I8 is rotated in a counterclockwisedirection, as viewed in Fig.

2, relative to the barrel sleeve Iii. When handle I1 is properlyadjusted relative to the barrel sleeve I0, screw 6 is turned in so thatthe end of such screw engages the walls of groove thereby securingsleeve I0 and handle I! against relative axial displacement. The wedgeshaped tooth 28" on the spring member .28 engages serrations 21 to holdhandle I! in the raised position, after unlocking barrel I from sleeveIt, preparatory to receiving the same or a new barrel. The member 28through its tooth 28" also retains handle IT in the locked position andagainst accidental movement by engagement with one of the serrations.29as previously mentioned.

Barrel I is rapidly changed by raising handle II until lug strikes stop40. In this position lugs I of sleeve II) have been rotated out of thepathof lugs 8 on barrel I so that barrel I may be quickly withdrawn fromreceiver I5 and bracket 31 from gas cylinder plug 35 by handle I6.Another barrel is readily inserted within sleeve Ii! and receiver I5 bymerely inserting the chamber end of the barrel within sleeve It (handleIt should be in the position shown in Fig. 1) and slipping bracket 3|over gas cylinder plug 35 until barrel shoulder II abuts sleeve I0, thenlowering handle 11 to the closed position. The headspace of the firearmhas been previously adjusted and has not been disturbed so that if thebarrels are properly interchangeable further headspace adjustment is notnecessary and the firearm is at once ready to fire.

Any firearm embodying this invention cannot be fired with the barrellocking handle I! in the unlocked position for when handle IT is inanything but the fully locked position of Fig. 4 the head d4 of theplunger 42 will be biased into the groove &3 of the operating slide 43by spring 45. Hence slid 43 cannot be released to load a cartridge Whilethe barrel is unlocked. The dangerous condition thereby eliminated isobvious. Closing handle ll causes arm I9 to bear against the end ofplunger 42 and when rotated .to the locked position, head 44 of plunger42 is forced out of the path of slide 43 against the bias of spring at.The firearm is then ready to load and fire.

After prolonged firing a deposit of carbon invariably forms around thegas port and surrounds the gas cylinder tube plug of any firearm. Withmost types of firearms it is extremely difiicult to remove the barrelfrom such a firearm because-of the freezing action due to the carbondeposit encountered at this point. With this invention, however, suchfreezing is very readily overcome by the camming action produced by theadvance of the barrel sleeve II) on the left hand threads 2 when arm I9is rotated to unlock the barrel from the barrel sleeve and receiver.Such rotation forces the barrel slightly forward from the receiver andin so doing easily breaks the seal between the bracket 3| and gascylinder tube plug 35 thereby permitting easy withdrawal of barrel Ifrom receiver I5.

From the foregoing description it is apparent that the headspacingfeature affords a convenient means for adjusting the headspace of afirearm. The quickly detachable barrel can easily be made to closemanufacturing tolerance limits so that each barrel even when made inlarge quantities, has practically identical measurements and is readilyinterchangeable, this is especially true with reference to the barrellugs. Therefore when once the firearm is adjusted for headspace with anyone barrel that particular barrel may be rapidly replaced by anotherwithout further attention to headspace adjustment of the firearm. In theevent it becomes necessary to replace some component of the firearm,such as the bolt forexample, the headspace may be readily adjusted bythe headspacing feature previously described. Hence any accumulation oftolerances on the components affecting headspace are readily taken careof by this headspacing feature.

I claim:

1. In a firearm having a barrel and receiver, a plurality of lockinglugs disposed around the periphery of the barrel, a locking sleevehaving spaced interior lugs corresponding to said looking lugs andarranged to permit the axial insertion of said barrel lugs thru saidsleeve in at least one angular position of said barrel with respect tosaid sleeve, said locking sleeve being threadably mounted to thereceiver whereby rotation of said sleeve will vary the longitudinalposition of said sleeve with respect to said receiver, an operatingmember adjacent said sleeve and axially movable with respect to saidsleeve, a plurality of serrations on said sleeve, toothed means on saidoperating member constructed and arranged to en- 7 gage a portion ofsaid plurality of serrations on said sleeve in one axial position ofsaid operating member with respect to said sleeve and to disengage saidserrations when said operating memher is axially moved relative to saidlocking sleeve, means for securing said operating member in said axialposition with respect to said sleeve and means for manuallyreciprocatingly rotating said operating member whereby said sleeve maybe rotated between a locking and unlocking position with respect to saidbarrel.

2. The combination as in claim 1 and means for limiting thereciprocating rotational movement of said operating member to theangular distance between the locked and unlocked rotational positions ofsaid sleeve with respect to the barrel, and means for resilientlysecuring said sleeve in both the locked and unlocked rotationalpositions.

3. In a firearm having a barrel and receiver, a plurality of lockinglugs disposed around the periphery of the barrel, a locking sleevehaving spaced interior lugs corresponding to said locking lugs andarranged to permit the axial insertion of said barrel lugs thru saidsleeve in at least one angular position of said barrel with respect tosaid sleeve, said locking sleeve being threadably mounted to thereceiver whereby rotation of said sleeve will vary the longitudinalposition of said sleeve with respect to said receiver, an annular recesson the periphery of said sleeve, an operating member surrounding saidsleeve in the vicinity of said annular recess and axially movable withrespect to said sleeve, screw means in said operating member cooperatingwith said annular recess to secure said operating member in a fixedaxial position with respect to said sleeve,

a plurality of serrations on said sleeve, a toothed portion on saidoperating member constructed and arranged to engage a portion of saidserrations when said operating member is secured by said screw means andto disengage said serrations when said operating member is moved axiallwith respect to said sleeve, means for manually reciprocatingly rotatingsaid operating member, means for limiting the reciprocating rotationalmovement of said operating member to ;he angular distance between thelocked and unlocked rotational positions of said sleeve with cespect tothe barrel, two spaced groups of serra- ;ions on said operating member,and a spring pressed toothed member on said receiver arranged 1o engagesaid serrations to resiliently secure said )perating member in eitherits barrel looking or inlocking rotational positions.

4. In a firearm having a receiver wherein a iarrel receiving lockingsleeve is rotatable with espect to the receiver and a barrel axially in-;ertable through said locking sleeve and arranged ,o be locked to thereceiver by rotation of the ocking sleeve, the improvement comprising an)perating member mounted on said sleeve for roatable and axialtranslative movement with re- :pect to said sleeve, releasable means forsecuring aid operating member against axial movement '0 a sleeveoperating position on said sleeve, and means for connecting saidoperating member fix- ;dly in angularly adjusted position on said sleeve:1 said secured position whereby said sleeve may re rotated by saidoperating member, said last mentioned means being constructed andarranged lie in disconnected relation to said operating dember and saidsleeve when said operating nember is in a position axially displacedfrom aid sleeve operating position, whereby the an- 8 gular position ofsaid operating member relative to said sleeve may be selectivelyadjusted.

5. In a firearm having a barrel and receiver, a plurality of lockinglugs fixed on and sp e around the periphery of the barrel, a lockingsleeve rotatably screw-mounted coaxially with the barrel on the receiverand having spaced interior lugs corresponding to said locking lugs andarranged to permit the axial insertion of said barrel through saidsleeve and passage of the barrel lugs between said lugs of the sleeve toan operating position of the barrel in the receiver in at least oneangular position of said barrel with respect to said sleeve, saidlocking lugs being of a length to lie longitudinally inward of the saidlugs on the sleeve at said operating position of the barrel to permitrelative rotation of the sleeve, an operating member for said sleevecoaxially rotatable in relation thereto and translatable axially withrespect to said sleeve, releasable means for securing said operatingmember against axial movement in an operating position in relation tosaid sleeve, and means for connecting said operating member fixedly inangularly adjusted position in relation to said sleeve whereby saidsleeve may be rotated by said oper ating member, said last mentionedmeans being constructed and arranged to disconnect said operating memberfrom said sleeve when said operating member is in a position displacedaxially from said operating position whereby the angular position ofsaid operating member relative to said sleeve may be selectivelyadjusted, said sleeve having an initial position in its rotation whereatit is in unlocked position longitudinally screwed along the barrel axisfrom locked position, and having its lugs aligned with the spacesbetween the said locking lugs.

6. In a firearm having a receiver, a locking sleeve rotatable withrespect to the receiver and a barrel axially insertable through saidlocking sleeve and arranged to be locked to the receiver by rotation ofthe locking sleeve, the improvement comprising an operating membermounted adjacent said sleeve for concentric rotative and axialtranslative movement with respect to said sleeve, releasable means forsecuring said operating member against axial movement in a positionimmediately adjacent said sleeve, a first circumferentially serratedsector on said sleeve and a second serrated sector on said operatingmember constructed and arranged to intermesh at one axial position ofsaid operating member relative to the sleeve and to clear each otherwhen the operating member is in a position axially displaced from saidone position, whereby said sleeve and operating member are releasablysecured together and angular position of said operating member relativeto said sleeve may be selectively adjusted.

7. In a firearm having a barrel and a receiver, a plurality of lockinglugs disposed around the periphery of the barrel, a locking sleevehaving spaced interior lugs corresponding to said looking lugs andarranged to permit the axial insertion of said barrel lugs thru saidsleeve in at least one angular position of said barrel with respect tosaid sleeve, said locking sleeve being threadably mounted to thereceiver whereby rotation of said sleeve will vary the longitudinalposition of said sleeve with respect to said receiver, an operatingsleeve surrounding a portion of said locking sleeve, said operatingsleeve being mounted for rotatable and axial movement with respect tosaid sleeve, a removable key in said operating sleeve cooperating with agroove in said locking sleeve to secure said operating sleeve in a fixedaxial position relative to said locking sleeve, a first gear-like sectoron said locking sleeve, a second gear-like sector on said operatingsleeve constructed and arranged to engage said first gear-like sector insaid secured position of said operating sleeve, whereby said lockingsleeve and operating sleeve are rotatively secured together, and todisengage from said first gear-like sector by axial movement of saidoperating sleeve from said secured position when said key has beenremoved from said groove, whereby the angular position of said operatingsleeve relative to said locking sleeve may be selectively adjusted.

8. In a firearm having a receiver and a reciprocating operating slide,the improvement comprising a locking sleeve rotatable with respect tothe receiver, a barrel axially insertable thru said locking sleeve andarranged to be locked to the receiver by rotation of the locking sleeve,an operating member constructed and arranged to rotate said lockingsleeve to its locked position relative to the receiver, and a stopmember spring biased into the path of the operating slide, saidoperating member being constructed and arranged to move said stop memberout of the path of the operating slide as said operating member moves toits barrel locking position.

9. In a firearm having a receiver and a reciprocating operating slide,the improvement comprising a locking sleeve rotatable with respect tothe receiver, a barrel axially insertable thru 10 said locking sleeveand arranged to be locked to the receiver by rotation of the lockingsleeve, an operating sleeve surrounding a portion of said lockingsleeve, means for rotatively securing said operating sleeve to saidlocking sleeve, a handle on said operating sleeve for rotating saidoperating sleeve and said locking sleeve to the barrel locking position,and a stop member spring biased into the path of the operating slide,said handle having a portion engaging said stop member to move said stopmember out of the path of the operating slide as said handle moves toits barrel locking position.

CLARENCE E. SIMPSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

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